Press and means for safeguarding same against excessive loads



Nov. 24, 1959 H. F. cLAAs ETAL PRESS AND ME 2,913,977 ANS FORSAFEGUARDING SAME AGAINST ExcEssIvE LoADS Flled April so. 195e 2Sheets-Sl'uaetl 1 MSB Filed April 30, 1956 NOV. 24, 1959 H, F, CLAASEI'AL PRESS AND MEANS FOR SAFEGUARDING SAME AGAINST EXCESSIVE LOADS 2Sheets-Sheet 2 -Mar Armen/Ey United States Patent O PRESS AND MEANS lFORSAFEGUARDING SAME AGAINST EXCESSIVE LOADS Application'Aplil 30, 1956,Serial No. 592,228

1 Claim. (Cl. 100-50) Our -invention relates to a press and moreparticularly to a press embodying means for safeguarding the press fromdamage by an excessive load. Our invention is specially applicable tohigh pressure baling presses for compressing bulky materials, such asstraw.

Prior presses of that kind are frequently liable to be damaged by beingsubjected to excessive pressures causing some structural elements, suchas the driving shaft, gears, container walls or plungers, to be stressedto an extent producing excessive deformations exceeding the elasticlimits.

It is an object of our invention to provide a safeguard protecting thepresses from damages by such excessive stresses.

It is a further object of the invention to provide a safeguard of simpledesign which is reliable in operation and may be easily applied toexisting presses without requiring basic structural changes thereof.

More particularly, it is an object of our invention to provide a presswith a safety device adapted, when the stresses set up in the structuralelements of the press exceed a certain limit, to discontinue theactuation of the press by disengaging a cluch or other driving means.

Finally, it is an object Aof our invention to provide a safeguard ofthecharacter indicated which will not be destroyed under excessive stressesand, therefore, is capable of repeated uses.

Further objects of our invention will appear from the following detaileddescription of a preferred embodiment, it being understood that theterms and phrases used in describing the invention have been chosen forthe purpose of illustrating the same rather than that of restricting orlimiting the invention, the features of novelty being pointed vout inthe appended claim. In the drawings:

Fig. l is a diagrammatical side elevational view of a high pressurepress for baling straw showing the laterally disposed actuating means,partly in section,

Fig. 2 is an end view of the press shown in Fig. 1 viewed from the frontwith respect to the direction of travel, and

Fig. 3 is a partial perspective illustration showing a stoppingmechanism adapted to be actuated by lateral deformation of a gear.

The high pressure straw-baling press 1 is supported by wheels 2 fortransportation purposes and is adapted to be towed by a tractor notshown by means of a thill 3, the tractor being of a known type having anoutput shaft 4 adapted to drive the press-actuating mechanism. The pressis provided with a pick-up mechanism 5 adapted to pick up the straw tobe baled, such straw being deposited by the pick-up mechanism in ahousing trough wherefrom it is fed by a feeder 6 into position in frontof a plunger 7 for subsequent compression thereby to bales in acontainer 8. The plunger 7 is of the oscillating type pivotallysuspended by means of plunger arms 36 (only one of the arms being shownin the drawings) and,

Patented Nov. 24, 1959 ICC adapted to be moved by connecting rods 37(only one of the rods being shown in the drawings) which are pivotallyconnected to crank pins carried by driving gears 15, 15'. The outputshaft 4 of the tractor is operative through the intermediary of a bevelgear transmission 9 to drive a pulley 10 adapted by means of a V-belt 11to drive the main drive shaft 13. Spur pinions 14 and 14 are fixed tothe main drive shaft 13 and are in mesh with the driving gears 1S, 15mounted on a shaft 16 journalled in the frame of the apparatus.

When the plunger 7 meets with an excessive resistance causing the shaft16 to be subjected to an excessive load, such shaft 16 will be flexedcausing the gears 15 and to be laterally displaced with respect to avertical plane in a slanting fashion. A movable member, such as theshort arm 17 of a bell crank 24 fulcrumed in a bracket 26 by means of apivot pin 25 and preferably provided with a roller 18 is mounted closeto the lateral face of the gear 15. The bracket 26 is fixed to wall 27of the frame of the press. Therefore, the lateral face of the gear 15,when laterally displaced in response to excossive stresses imposed onthe shaft 16, will engage the roller 18 and will swing the bell crank 24about the pivot pin 25. The lever 19 of the bell crank is connected by alink 20 to an upright arm Z1 of a short horizontal shaft carrying adownwardly extending short `arm Z2. The latter is connected by aconnecting rod 23 with an arm of the housing of the bevel geartransmission 9. The connecting rod 23 is threaded and is adjustablyconnected with such arm by a pair of nuts. The housing 9 is guided inthe frame of the press for vertical adjustment by suitable means notshown.

When the arm 22 is .turned in the direction indicated by the arrow inFig. 3 in response to the overload condition, it lifts the connectingrod 23, the latter lifting the housing 9 of the bevel gear transmissionandthe V-belt pulley 10 journalled therein. As a result, lthe frictionalengagement of the V-belt 11 in the grooves of thefpulley 10 will beeliminated, whereby the actuation of the plunger 7 is terminated. Theadjustable connection provided between the connecting rod 23 and thehousing yof the transmission 9 by means of the nuts permits the pulley10 to be adjusted for the purpose of controlling the tension of theV-belt. The roller 18 is capableof adjustment relative to the lgear 15by an adjusting nut 28 provided on the link 20. Moreover, a set screw 29is provided acting as a stop for limiting the swinging move-` ment ofarm 21. a .Y l

The pressure exerted on the plunger 7 by the material to be baled istransferred by means of the connecting rods 37 and the crank pins to thedriving gears 15 and 15 exerting a couple thereon. It is this couplewhich exes the shaft 16 causing the gears 15 and 15 to be displaced in aslanting fashion. The lateral displacement of the gears 15 and 15 willbe greatest in the lower dead center position of the crank pins as inthis position of the crank pins the plunger will have compressed Vthestraw to a bale and thus will be subjected to the maximum load. For thisreason, the arm 17 of the bell crank 24 is preferably provided at theposition shown where the couple acting on the gears 15 and 15 producesthe maximum lateral deflection when the plunger is in its flower deadcenter position.

From the foregoing description it will appear that the roller 18measures the deformation of the structural element, such as gear 15, ofthe press and performs a safeguarding operation, such as the lifting ofthe bevel gear housing 9, in response to the deformation exceeding apredetermined limit. Pulley 10 and the belt 11 constitute, in elect, asafety clutch which may be actuated by vertical displacement of thetransmission gear housing 9.

As will appear from the foregoing description, the

press is safeguarded from damage by the provision of safety means whichare actuated in response to elastic deformation of the structuralelements of the press caused by high stresses to thereby stop themachine and save it from damage. As in high pressure baling presses thedeflection of the plunger driving shaft is commensurate with thestresses set up in the press, it is possible to cause such deformationto act on the safety means which stop the press in a purely mechanicalmanner.

It is well known in the prior art to safeguard machines from damage byoverload through the use of slip clutches or belt drives capable ofslippage under excessive load or by so-called shear pins. The presentinvention solves the problem in a novel fashion. As distinguished fromshear pins, the novel safety mechanism will not be destroyed under anoverload. It does not require any additional clutches. It permits torepeat the safeguarding action as often as desired by the use ofreversible means. The invention makes use of the large vertical andhorizontal dimensions of the structural elements of baling presses andfurther makes use of the liberty of relative movement of the structuralelements, such movement taking place with a high ration of transmission.

It has been found that when the baling press is subjected to anexcessive load, the plunger operating shaft, such as shaft 16 in Fig. 2,will be ilexed causing the gears and 15' mounted thereon to assume aslanting position differing from the normal vertical position. Theslanting position of the gear causes the same to wobble during itsrotation. The maximum deection occurs at the time when the plungerarrives in the dead center position subjecting the press to the maximumload. Therefore, the roller, such as 18, is disposed in slightly spacedrelationship from the outside of the gear 15, mounted on the plungerdriving shaft and, therefore, permits the gear in .the normal operationto revolve freely. The roller may be mounted on an arm of a bell crank,such as 24, fulcrumed for pivotal motion about a Xed pivot. The arms ofthe bell crank are preferably so dimensioned that a sufficiently largestroke will be imparted to the longer arm thereof to stop the operationof the press through the intermediary of another pair of arms, such as21, 22, fulcrumed on the frame of the press. As soon as the plungerdriving shaft is subjected to an abnormal load, the gear, owing to theflexion of the shaft, will assume a position dilering from its normalvertical position and will contact the roller 18, causing the roller tobe urged laterally to thereby swing the bell crank.

While in the embodiments described hereinabove the structural elementsubject to deformation is a gear, such as gear 15, it may be any othersuitable element of the press, for instance the plunger 7 or a wall ofthe container 8 which is likewise subject to elastic deformation.

While the invention has been described in connection with a singleembodiment thereof, it will be understood that it is capable of furthermodifications, and this application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure as come within known or customary practice in the artto which the invention pertains, and as fall within the scope of theinvention or the limits of the appended claim.

What we claim is:

In a press for baling straw and like materials, in cornbination: aplurality of structural elements including a container for receiving thematerials and a plunger reciprocable into and out of said container forcompressing the materials when advanced into said container, at leastone of said structural elements being progressively deformable inresponse to increasing pressures with which the materials in saidcontainer resist the compressing action of said plunger; means drivinglyconnected with said plunger `for reciprocating same, said meanscomprising an endless flexible element and a device for driving saidflexible'element; and means for bodily moving said device from drivingengagement with said eXible element, said last mentioned meanscomprising an articulatable linkage having a rst end connected with saiddevice and a second end adjacent to said one structural element anddisplaceable by the latter at least at such times when the deformationof said one structural element attains a given magnitude, said deviceremaining in driving engagement with said flexible element when thedeformation of said one structural element is below said vgivenmagnitude and being moved by said rst end out of driving engagement withsaid flexible element when the second end is displaced by said onestructural element and the latters deformation attains said givenmagnitude, the construction of said linkage being such that thedisplacements of said second end are transmitted to said rst end at ahigher ratio.

References Cited in the file of this patent UNITED STATES PATENTS

